Analysis of the Atomic Bomb
Kategorie: Fyzika a astronómia (celkem: 480 referátů a seminárek)
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- Přidal/a: anonymous
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Analysis of the Atomic Bomb
Ever since the dawn of time man has found new ways of killing each other. The most destructive way of killing people known to man would have to be the atomic bomb. The reason why the atomic bomb is so destructive is that when it is detonated, it has more than one effect. The effects of the atomic bomb are so great that Nikita Khrushchev said that the survivors would envy the dead (International Physicians for the Prevention of Nuclear War, 1982). These devastating physical effects come from the atomic bomb’s blast, the atomic bomb’s thermal radiation, and the atomic bomb’s nuclear radiation.An atomic bomb is any weapon that gets its destructive power from an atom. This power comes when the matter inside of the atoms is transformed into energy. The process by which this is done is known as fission. The only two atoms suitable for fissioning are the uranium isotope U-235 and the plutonium isotope Pu-239 (Outlaw Labs). Fission occurs when a neutron, a subatomic particle with no
electrical charge, strikes the nucleus of one of these isotopes and causes it to split apart. When the nucleus is split, a large amount of energy is produced, and more free neutrons are also released. These neutrons then in turn strike other atoms, which causes more energy to be released. If this process is repeated, a self-sustaining chain reaction will occur, and it is this chain reaction that causes the atomic bomb to have its destructive power (World Book, 1990). This chain reaction can be attained in two different ways.
The first type of atomic bomb ever used was a gun-type. In this type two subcritical pieces of U-235 are placed in a device similar to the barrel of an artillery shell. One piece is placed at one end of the barrel and will remain there at rest. The other subcritical mass is placed at the other end of the barrel. A conventional explosive is packed behind the second subcritical mass. When the fuse is triggered, a conventional explosion causes the second subcritical mass to be propelled at a high velocity into the first subcritical mass. The resulting combination causes the two subcritical masses to become a supercritical mass. When this supercritical mass is obtained, a rapid self-sustained chain reaction is caused (World Book, 1990). This type of atomic bomb was used on Hiroshima, and given the nickname “Little Boy” after Franklin D. Roosevelt (Outlaw Labs).
The second type of atomic bomb is an implosion bomb.
In this type a subcritical mass, which is in the shape of a ball, is placed in the center of the weapon. This subcritical mass is surrounded in a spherical arrangement of conventional explosives. When the fuse is triggered all of the conventional explosives explode at the same time. This causes the subcritical mass to be compressed into a smaller volume, thus creating a supercritical mass to be formed. After this supercritical mass is obtained, a self-sustained chain reaction takes place and causes the atomic explosion (World Book, 1990). This type of stomic bomb was used on Nagasaki, and given the nickname “Fat Man” after Winston Churchill (Outlaw Labs).
The blast from an atomic bomb’s explosion will last for only one-half to one second, but in this amount of time a great deal of damage is done (Physicians and Scientists on Nuclear War, 1981). A fireball is created by the blast, which consists mainly of dust and gasses. The dust produced in this fireball has no substantial effect on humans or their environment. However, as the gasses expand a blast wave is produced. As this blast wave moves, it creates static overpressure. This static overpressure then in turn creates dynamic pressure. The static overpressure has the power to crush buildings. The dynamic pressure creates winds, which have the power to blow down trees (International Physicians for the Prevention of Nuclear War, 1982). The blast pressure and fireball together only last for approximately eleven seconds, but because it contaitns fifty percent of the atomic bomb’s latent energy a great deal of destruction occures (The Committee for the Compilation of Materials on Damage Caused by the Atomic Bombs in Hiroshima and Nagasaki, 1981).
In Hiroshima the blast from the atomic bomb was measured to be about four and a half to six and seven tenths tons of pressure per square mere, while in Nagasaki the blast was measured to be about six to eight tons of pressure per square meter (International Physicians for the Prevention of Nuclear War, 1982). Because of thsidramatic change in the pressure most of the cities were destroyed. The static overpressure in Hiroshima caused ninety-one and nine tenths percent of all the buildings to be destroyed, while in Nagasaki it casued thirty-six and one tenth of all of the buildings to be destroyed. The static overpressure created a dynamic pressure that had winds up to four hundred miles per hour (The Committee for the Compilation of Materials on Damage Caused by the Atomic Bombs in Hiroshima and Nagasaki, 1981).
These winds caused minor scrathces, lacerations, or compound fractures, which came about when people and glass fragments were projected through the air. By combining the results of the static overpressure and the dynamic pressure on can begin to see what damage was caused by the atomic bomb’s blast. The total number affected in Hiroshima was approximately seventy-eight thousand people, while in Nagasaki the total number affected was approximately forty-five thousand people (International Physicians for the Prevention of Nuclear War, 1982).
The thermal radiation produced by an atomic bomb explosion will account for thirty-five percent of the atomic bomb’s damage. Thermal radiation can come in either one of three forms; ultraviolet radiation, visible radiation, or infrared radiation. The ultraviolet radiation is absorbed so rapidly by air particles that it has no substantial effect on people (World Book, 1990). However, the visible and infrared radiation creates an enormous amount of heat to be produced, approximately ten million degrees Celsius at the hypocenter (Physicians and Scientists on Nuclear War, 1981). This heat has two main effects. The first is known as flash burns. These flash burns are produced by the flash of thermal radiation right after the explosion. Flash burns can be either first degree burns (bad sun burns), second degree burns ( blisters, infections, and scars), or third degree burns (destroyed skin tissue). The second type is known as flame burns. These are burns that come from one of two different types of fires, which are created when flammable materials are ignited by the thermal radiation. The first type is called firestorms. A firestorm is violent, has raging winds, and has extremely high temperatures; but fortunately it does not spread very rapidly. The second type is called a conflagration. A conflagration is when the fire spreads in a front (International Physicians for the Prevention of Nuclear War, 1982). The thermal radiation produced by the atomic bomb’s explosion will account for most of the deaths or injuries.
In Hiroshima and Nagasaki the thermal radiation accounted for approximately twenty to thirty percent of the deaths or injuries from the atomic bomb’s explosion. Those that were at a distance of four and two hundredths of a kilometer from the hypocenter received first degree burns. Those that were at a distance of three and one half kilometers from the hypocenter received second degree burns.
Those that were at a distance of ninety-seven hundredths of a kilometer from the hypocenter received third degree burns (International Physicains for the Prevention of Nuclear War, 1982). Ninety-five percent of the burns created from the thermal radiation were by flash burns, and only five percent of the burns were by flame burns. The reason for this low number of flame burns is that only two to ten percent of the buildings caught on fire (International Physicians for the Prevention of Nuclear War, 1982). By combining the damage from both the flash and flame burns one can begin to see the effects that an atomic bomb’s thermal radiation had. Approximately sixty thousand in Hiroshima, and approximately forty-one thousand people were either killed or injured from the thermal radiation (The
Committee for the Compliation of Materials on Damage Caused by the Atomic Bombs in Hiroshima and Nagasaki, 1981).
The final effect that an atomic bomb caused is the nuclear radiation produced from the fission process. The cuclear radiation comes in the form of either Gamma rays or Beta particles. Gamma rays
are electromagnetic radiation originating in the atomic nuclei, physically identical to x-rays. They can enter into living tissue extremely easily. Beta particles are negatively charged particles, identical to an electron moving at a high velocity (International Physicians for the Prevention of Nuclear War, 1982). These forms of nuclear radiation are measured in rads (radiation-absorbed-dose), which is defined as teh absorption of five ten millionths joule per gram of abosorbing material (International Physicians for the Prevention of Nuclear War, 1982). During the initial nuclear radiation mostly Gamma rays are emitted from the fireball. This period of initial nuclear radiation lasts for approximately one minute. During the residual nuclear period (fallout) the Beta particles and more of the Gamma rays are emitted. The residual radiation has two stages: early fallout and delayed fallout. In early fallout, the heavyand highly radioactive particles fall back to the earth, usually within the first twenty-four hours. In delayed
fallout, the tiny and often invisible particles fall back to the earth, and usually last from a couple od days to several years (Physicians and Scientists on Nuclear War, 1981 and World Book, 1990). The nuclear radiation from the atomic bomb’s explosion was not the main cause of death, but it did still have serious results.
In Hiroshima, the initial nuclear radiation was spread over a distance of approximately fifty-three hundredths of a kilometer.
In Nagasaki, the initial nuclear radiation only spread one and six thousandths of a kilometer (The Committee for the Compilation of Materials on Damage Caused by the Atomic Bombs in Hiroshima and Nagasaki, 1981). The reason why the nuclear radiation was not the main caused of deaths or injuries was that the atomic bomb was detonated so high in the atmosphere; approximately five hundred and seventy meters in Hiroshima, and approximately five hundred and ten meters in Nagasaki (Outlaw Labs). Even without causing many deaths the nuclear radiation probably caused the most serious effects. Those with definite proof were those of increased rates of cataracts, leukemia, cancer of the thyroid, cancer of the breast, cancer of the lungs, cancer of the stomach, and mental retardation on babies in utero. Those that had substantial but not definite proof were those of tumors of the esophagus, tumors of the colon, tumors of the salivary glands, and tumors of the urinary tract organs. Those that had no definite nor substantial proof were those of increased rates of birth mortality, birth defects, infertility, and susceptibility towards illnesses (Physicians and Scientists on Nuclear War, 1981). The total number of people effected by the nuclear radiation was estimated to be thiry-five thousand people in Hiroshima, and twenty-one thousand people in Nagasaki (The Committee on Damage Caused by the Atomic Bomb in Hiroshima and Nagasaki).
Either the blast, the thermal radiation, or the nuclear radiation from an atomic bomb explosion will have severe effects on both humans and on the environment in which they live in. The only two cities that have ever experienced having an atomic bomb being exploded on them were the Japanese cities of Hiroshima and Nagasaki during World War II. In Hirsohima, the total number killed was one hundred and eithteen thousand six hundred and sixty-one. The total number severely injured was thrity thousand five hundred and twenty-four. The number slightly injured was forty-eight thousadn six hundred and six. The total number missing was three thousand and six hundred and seventy-seven. In Nagasaki, the total number killed was seventy-three thousand eitght hundred and eighty-four. The total number severely injured was seventy-four thousand nine hundred and nine. The total number slightly injured was one hundred and twenty thousand eight hundred and twenty (The Committee for the Compliation of Materials on Damage Caused by the Atomic Bombs in Hiroshima and Nagasaki, 1981).
With statistics like these it is clearly seen that Pope John Paul II was right when he said,
“Any nuclear war would inevitably cause death, disease, and suffering of pandemic proportions and without the possibility of effective medical intervention. The only hope for humanity is prevention of any form of Nuclear War."
The examples of Hiroshima and Nagasaki will hopefully be the first and the last time that the power of the atomic bomb will ever be used.